The Solar System:

Earth


"Gaea" (1875 CE) by Anselm Feuerbach; ceiling painting in the Academy of Fine Arts, Vienna. Also spelled Gaia, she was the Greek personification of the Earth and a primordial deity. Her children included Uranus (the sky) and the Titans.

Credit(s): Public Domain, Wikimedia Commons [link]

Earth in pictures (from space)

Earthrise, taken on 24 December 1968 by Apollo 8 astronaut William Anders.

Credit(s): Public Domain; NASA/Bill Anders [link]

Earth and the Moon from Apollo 11. This photo of the Apollo 11 lunar lander "Eagle" descending to the surface of the Moon in 1969 carrying astronauts Neil Armstrong and Buzz Aldrin was taken by astronaut Michael Collins, who remained in lunar orbit in the Apollo command module "Columbia". With the entire Earth in view as well as the lander, Collins was the only human being in the Universe not in the frame of this photo.

Credit(s): Public Domain; NASA/Michael Collins

The Blue Marble, taken by the Apollo 17 crew in 1972 while en route to the Moon. The image shows Africa (upper left), the Arabian Peninsula (top), and Antarctica (bottom).

Credit(s): Public Domain; NASA/Apollo 17 crew

Earth (lower right), as seen from the Artemis 1 mission to the Moon on 16 November 2022. The aft end of the Orion crew capsule (with no astronauts aboard for this mission) is visible on the left.

Credit(s): Public Domain; NASA

The image combines two separate exposures taken on 20 November 2016 by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. For presentation, the exposures were processed separately to optimize detail visible on both Earth and the moon. The moon is much darker than Earth and would barely be visible if shown at the same brightness scale as Earth.

The combined view retains the correct positions and sizes of the two bodies relative to each other. The distance between Earth and the moon is about 30 times the diameter of Earth. Earth and the moon appear closer than they actually are in this image because the observation was planned for a time at which the moon was almost directly behind Earth, from Mars' point of view, to see the Earth-facing side of the moon.

In the image, the reddish feature near the middle of the face of Earth is Australia. When the component images were taken, Mars was about 127 million miles (205 million kilometers) from Earth.

Credit(s): (image and text) NASA/JPL-Caltech/Univ. of Arizona [link]

The Pale Blue Dot

For the 30th anniversary of one of the most iconic images taken by NASA's Voyager mission, a new version of the image known as "the Pale Blue Dot."

Planet Earth is visible as a bright speck within the sunbeam just right of center and appears softly blue, as in the original version published in 1990 (see PIA00452).

This updated version uses modern image-processing software and techniques to revisit the well-known Voyager view while attempting to respect the original data and intent of those who planned the images.

In 1990, the Voyager project planned to shut off the Voyager 1 spacecraft's imaging cameras to conserve power and because the probe, along with its sibling Voyager 2, would not fly close enough to any other objects to take pictures. Before the shutdown, the mission commanded the probe to take a series of 60 images designed to produce what they termed the "Family Portrait of the Solar System." Executed on Valentine's Day 1990, this sequence returned images for making color views of six of the solar system's planets and also imaged the Sun in monochrome.

The popular name of this view is traced to the title of the 1994 book by Voyager imaging scientist Carl Sagan, who originated the idea of using Voyager's cameras to image the distant Earth and played a critical role in enabling the family portrait images to be taken.

The image of Earth was originally published by NASA in 1990. It was reprocessed and republished in 2020 to commemorate the 30th anniversary of the Family Portrait of the Solar System (see PIA00451) and the Pale Blue Dot image in particular.

Our home planet occupies less than a single pixel in the image and thus is not fully resolved. (The actual width of the planet on the sky was less than one pixel in Voyager's camera.) By contrast, Jupiter and Saturn were large enough to fill a full pixel in their family portrait images.

The direction of the Sun is toward the bottom of the view (where the image is brightest). Rays of sunlight scattered within the camera optics stretch across the scene. One of those light rays happens to have intersected dramatically with Earth. From Voyager 1's vantage point — a distance of approximately 3.8 billion miles (6 billion kilometers) — Earth was separated from the Sun by only a few degrees. The close proximity of the inner planets to the Sun was a key factor preventing these images from being taken earlier in the mission, as our star was still close and bright enough to damage the cameras with its blinding glare.

Like the original version, this is technically a "false-color" view, as the color-filter images used were mapped to red, green and blue, respectively. The brightness of each color channel was balanced relative to the others, which is likely why the scene appears brighter but less grainy than the original. In addition, the color was balanced so that the main sunbeam (which overlays Earth) appears white, like the white light of the Sun.

The image was processed by JPL engineer and image processing enthusiast Kevin M. Gill with input from two of the image's original planners, Candy Hansen and William Kosmann.

The reprocessed 30th Anniversary Pale Blue Dot image. Earth is the bright speck located near the middle of the bright ray of sunlight just right of center.

Credit(s): (image and text) Public Domain; NASA/JPL-Caltech [link]

Zoomed view of Earth in the reprocessed 30th Anniversary Pale Blue Dot image.

Credit(s): (image and text) Public Domain; NASA/JPL-Caltech [link]